Casing cutter



J. J. MCCANN CASING CUTTER May 16, 1939.

Filed March s, 193e Juve/W10@ wnmmm@ Patented May 16, 1939 PATENT OFFICECASING CUTTER,

Judson J. McCann, Lake Charles, La.

Application March 3, 1938, Serial No. 193,774

4 Claims.

This invention relates to a. casing cutter and has relation moreparticularly to that type known as inside cutter, and it is primarily anobject of the invention to provide a tool of this kind which can be usedto bring in wells from open sand at any depth afterk the casing has beenset to a depth.

It is also an object of the invention to provide a cutter of this kindembodying cutting members adapted to maintain effective cutting relationwith respect to the casing to be cut by uid pres- Vantageous for use, aswill be hereinafter more lll) fully set forth.

The novel features of my invention will hereinafter be definitelyclaimed.

In order that my invention may be the better understood, I will nowproceed to describe the same with reference to the accompanying drawing,wherein:

` Figure 1 is a sectional view with parts in elevation of a cutterconstructed in accordance with an embodiment of my invention and inapplied position within a casing, the cutting members being shownretracted in full lines and the extended adjustment of the cutters beingindicated by broken lines;

Figure 2 is an enlarged fragmentary sectional view with parts inelevation showing the cutting members fully extended and after cuttingthrough the casing;

Figure 3 is a sectional view taken substantially on the line 3-3 ofFigure l, the casing being omitted.

As disclosed in the accompanying drawing, C denotes a casing in which myimproved tool is adapted to work. As herein disclosed my improved toolcomprises an elongated tubular central body I having a top section orhead 2 threaded thereon and the lower end portion of the section I hasthreaded therein a bottom section 3. This bottom section 3, as hereindisclosed, has an extension lll which slips up within the lower portionof the bore of the member or section I and this bottom section 3 and itsextension 4 have provided therethrough a bore 5 opening into the bore aof the section or member I. The side wall of the member or section I atequidistantly spaced points therearo-und is provided with thelongitudinally disposed slots 6 herein disclosed as four in number, andthe top wall of each of the openings 6 is disposed on an upward andinward bevel,

as at l, of approximately forty-rive degrees although this angle may bevaried as preferred.

Intersecting each of the slots or openings 6 at the upper portionthereof is a pivot pin 8 upon l which is mounted for rocking movement acutting member or mill 9. The cutting member or mill 9 is extended atits pivoted end by an upwardly disposed tail piece I which has its outerface inwardly tapered whereby the outer or upper extremity of the tailpiece I0 is pointed for effective engagement within an annular pocket orrecess I I provided in the under or lower end face of a mandrel I2. Thismandrel I2, as herein disclosed, is integrally formed with an elongatedtubular rod I4 open at both ends and the lower end portion of which atall times is telescopically engaged within the bore of the extension 4of the lower section 3.

The mandrel I2 snugly engages within the bore a of the section I butfreely moves therealong. The upward movement of this mandrel I2 and alsoof the rod I4 is limited by contact of the mandrel I2 with an inwardlydisposed internal annular flange I5 positioned substantially midway thelength of the section I. This flange I5 defines a central openingthrough which the upper portion of the rod I4 is snugly and slidablydirected. This flange I5 also provides a stop or abutment for anexpansible member I6 of desired tension and which is herein disclosed asa coil spring encircling the portion of the rod I4 above the flange I5.`This member or spring I6 also bears against a piston I1 preferably ofrubber andwhich piston is snugly fitted within the upper portion of thebore a of the section I.

The rod I4 extends, as at I8, above the piston I 'I and suitably securedto said extended portion I8 is a cage I9 for a valve member 20, hereindisclosed as a ball, whichoperates to prevent downward Vor retrograde owthrough the bore of the rod I4. The member or spring I6 is of a tensionsuicient to normally maintain the mandrel I2 at the limit of its upwardmovement so that the supplemental mandrel 2 I, carried by the rod I4 ata desired distance below the mandrel I2, will maintain the cuttingmembers or mills 9 in their fully retracted position as is 'illustratedin Figure 1. It is to be noted that the inner face of each of thecutting members or mills 9 including the tail piece Il! is straight fromend to'end so that the mandrel 2| may readily contact therewith andmaintain the cutting member or mill 9 fully retracted undernormalconditions.

The upper portion of the mandrel 2| is inwardly tapered, as at 22, tofacilitate the desired action of the mandrel upon the cutting members ormills as the rod I4 is moved upwardly under the action of the member orspring I6 to return the mandrel I2 to its normal position. To assure thedesired functioning of the mandrel 2| it must, of course, be of adiameter l-ess than the diameter of the bore a of the section I.

The pocket or recess II in the under surface of the mandrel I2 generallyspeaking is conoidal, that is to say, its bottom wall is inclinedinwardly and upwardly so that as the rod I4 is forced downwardly thecontact of the mandrel I2 with the pointed extremities of the tailpieces Ill for the cutting members or mills 9 will cause the lower endsof the cutting members or mills 9 to be forced outwardly through theslots 6 into contact from within the casing C so that as the rotarymechanism is put into operation the cutting members or mills; 9 willhave proper cutting engagement with the casing and so maintained untilthe casing is entirely cut through.

The top section 2 is adapted to be coupled, as at 23, with a stem orstring 24 through the medium of which the tool is lowered t the desireddepth within the casing. After the tool has been lowered as desired, thepump is started and the pressure of the mud received within the sectionI above the piston I'I will force said piston downwardly to make theproper contact of the members or mills 9 with the casing C and maintainsuch contact until the casing is completely cut out. At the completionof this cutting action the pressure upon the piston will then force thesame beyond the suitably positioned iluid outlets 25 which are continuedby the pipes 26 to a point adjacent the members or mills 9. When theseoutlets 25 are opened the pressure of the pump will be relievedpermitting such pressure to run freely and thus indicating to theoperator that the casing has been cut through. Upon stopping of the pumpthe member or spring IS will cause the rod I4 to move upwardly to bringthe mandrel I2 to its normal position with a resultant retraction of themembers or mills 9.

When the pump is in operation the valve member 20 will close the bore ofthe rod I4 against ow therethru. However, in lowering'the tool withinthe casing this valve 20 will readily open to relieve any resistingpressure which may be offered to such lowering of the tool.

While I have particularly referred to my improved tool as a casingcutter, it is to be understood that after the casing has been cutthrough weight can be applied and a section of the casing milled away inorder to leave an open section where there is clean oil sand.

From the foregoing description it is thought to be obvious that a casingcutter constructed in accordance with my invention is particularly welladapted for use by reason of the convenience and facility with which itmay be assembled and operated, and it will also be obvious that myinvention is susceptible of some change and modification withoutdeparting from the principles and spirit thereof and for this reason Ido not wish to be understood as limiting myself to the precisearrangement and formation of the several parts herein shown in carryingout my invention in practice except as hereinafter claimed.

I claim:

1. A casing cutter comprising an elongated tubular section, a tubularbottom section engaged therewith, an elongated rod within the elongatedsection .and having an end portion telescoping in the bottom section, apiston carried by the opposite end portion of the rod and snuglyengaging within the elongated section, a top section for the elongatedsection, said top section having connection with a stem, said elongatedsection having an internal shoulder, an expansible member interposedbetween the shoulder and the piston, slots in the lower portion of theWall of the elongated section, cutting members, means for pivoting saidmembers to the elongated section to allow said members to swingoutwardly through the slots, said cutter members having upwardlydisposed tail pieces, said tubular rod having a conoidal face to engagethe tail pieces for swinging the cutting members outwardly upon downwardmovement of the piston and rod, the inner faces of the cutting membersbeing straight, and a mandrel carried by the rod for engagement with thestraight faces of the cutting members for retracing the cutting membersand maintaining such members retracted upon upward movement of the rodand piston.

2. A casing cutter comprising an elongated tubular section, a tubularbottom section engaged therewith, an elongated rod within the elongatedsection and having an end portion telescoping in the bottom section, apiston carried by the opposite end portion of the rod and snuglyengaging within the elongated section, a top section for the elongatedsection, said top section having connection with a stem, said elongatedsection having an internal shoulder, an expansible member interposedbetween the shoulder and the piston, slots in the lower portion of thewall of the elongated section, cutting members, means for pivoting saidmembers to the elongated section to allow said members to swingoutwardly through the slots, said cutting members having upwardlydisposed tail pieces,

and a mandrel carried by the rod, said mandrel having its bottom faceconoidal to engage the tail pieces as the rod moves downwardly to swingthe cutting members out through the slots.

3. A casing cutter comprising a tubular member having a slot in its sidewall, a cutting member, means for pivotally mounting the cutting memberupon the tubular member, said member having a tail piece extendingwithin the tubular member in all positions of the cutting member aboutits pivot, and a movable actuator within the body for the cuttingmember, said actuator having means thereon to engage one edge face ofthe cutting member upon movement of the actuator in one direction tomove the cutting member outwardly from the body thru the slot, saidactuator having additional means to contact with a second edge face ofthe tail piesv of the cutting member upon movement of the actuator inthe opposite direction to retract the cutting member.

4. A casing cutter comprising a tubular member having a slot in a wallthereof, a cutting member pivot-ally carried by the tubular member andhaving movement inwardly and outwardly of said member through the slot,said cutting member having a tail piece extending within the tubularmember, a movable actuator for the cutting member within said tubularmember, said actuator having a conoidal recess, the wall of whichcontacting with one edge of the tail piece upon movement of the actuatorin one direction to swing the cutting member outwardly beyond thetubular member, said actuator also having a tapered portion forcontactwith a second edge face of the tail piece upon movement of theactuator in the opposite direction to retract the cutting member. i

JUDSON J. MCCANN.

